FLEXBEAM REDIRECTIONAL SYSTEM FOR THE MODULAR CRASH CUSHION

THE MODULAR CRASH CUSHION, THROUGH TESTING AND FIELD EXPERIENCE, HAS PROVED TO BE AN EFFECTIVE IMPACT ATTENUATOR BETWEEN AUTOMOBILES AND RIGID OBSTACLES. WHILE THE MODULAR CRASH CUSHION DESIGN WHICH IS NOW IN FIELD USE HAS PROVEN TO BE HIGHLY SUCCESSFUL, ESPECIALLY IN HEAD-ON COLLISIONS, IT DOES HAVE A POTENTIAL DANGER ZONE NEAR THE BACK OF THE CUSHION. WHEN IMPACTING IN THIS DANGER ZONE, A VEHICLE CAN POCKET AND CONTACT THE RIGID OBSTACLE BEFORE LOSING A SIGNIFICANT AMOUNT OF ENERGY. IT IS EVIDENT THAT, IN THIS DANGER ZONE, REDIRECTION WOULD NORMALLY BE MORE DESIRABLE THAN COMPLETE ARRESTMENT. A POSSIBLE MODIFICATION, INTENDED TO PRODUCE THE NEEDED REDIRECTIONAL CAPABILITY IN THIS DANGER ZONE, WAS EVALUATED BY THREE VEHICLE CRASH TESTS. THE TEST RESULTS INDICATED THAT THE INCLUSION OF A W-SECTION GUARDRAIL AROUND A SET OF DRUMS ADDED TO THE REAR PORTION OF THE CRASH CUSHION CAN PROVIDE REDIRECTIONAL CAPABILITY FOR ANGULAR CRASHES NEAR THE RIGID OBSTACLE IF ADEQUATELY SUPPORTED BY FIXED POSTS AND RIGID CABLE CONNECTIONS. HOWEVER, FOR ANGULAR HITS DIRECTLY IN FRONT OF THE GUARDRAIL PORTION, THE VEHICLE WILL "POCKET" AND THEN ENCOUNTER THE GUARDRAIL AT A SEVERE ANGLE. THIS TENDS TO CAUSE THE VEHICLE TO BOTH SPIN AND REBOUND. NEVERTHELESS, THE DECELERATIONS PRODUCED IN SUCH A TEST ARE NOT CONSIDERED EXCESSIVE FOR PROPERLY RESTRAINED PASSENGERS. IT WAS EVIDENT FROM THE TESTS THAT THE LONGITUDINAL CABLES ATTACHED TO THE FLEXBEAM FORM AN INTEGRAL PART OF THE FLEXBEAM REDIRECTION SYSTEM. THESE CABLES MUST PROVIDE LATERAL STABILITY IN ANGLED IMPACTS WHILE PRODUCING NEGLIGIBLE INTERFERENCE IN HEAD-ON CRASHES. ONE (UNSUCCESSFUL) TEST REPORTED HERE DEMONSTRATED THE NEED FOR STRONG AND RIGID CABLE CONNECTORS, AND SEVERAL FIXED POSTS SUPPORTING THE GUARDRAIL. DRAWINGS OF A REVISED DESIGN INCORPORATING THESE FEATURES ARE PRESENTED IN THE REPORT. IT WOULD BE DESIRABLE TO EVALUATE THIS REVISED DESIGN WITH A FULL-SCALE CRASH TEST. /AUTHOR/

  • Supplemental Notes:
    • Rpt No 146-3, 38 PP, 31 FIG, 3 TAB, 4 REF, 1 APP
  • Corporate Authors:

    Texas Transportation Institute

    Texas A&M University System, 1600 E Lamar Boulevard
    Arlington, TX  USA  76011
  • Authors:
    • Hayes, G G
    • Ivey, D L
    • Hirsch, T J
  • Publication Date: 1970-10

Subject/Index Terms

Filing Info

  • Accession Number: 00203595
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Mar 27 1972 12:00AM